The present invention relates to a keyboard unit having a displacement member that is displaced in a forward stroke direction and a returning direction by key pressing/releasing operation.
Keyboard musical instruments are available that have a displacement member, such as a hammer or the like, that is driven directly or indirectly with a key by the pressing operation of the key and is displaced (moved) in a forward stroke direction. In this kind of musical instrument, a keyboard musical instrument is also available in which the operation of a key or a displacement member is detected and musical sound is controlled on the basis of the result of the detection. For example, in the technology disclosed in JP-A-2010-160263, three or more contact sections that are turned ON sequentially according to key pressing operation are provided, and the key pressing velocity and sound generation timing are controlled when two contact sections corresponding to a designated performance style are turned ON sequentially.
Generally, in a musical instrument in which the operation of a displacement member, such as a hammer, operating in synchronization with a key is used for musical sound control, the control is carried out on the implicit premise that the displacement member operates almost accurately in synchronization with the key in all performance styles.
However, in reality, for example, the key and the hammer do not always operate accurately in synchronization with each other, and the relative relationship between the key and the hammer is complicated depending on various key pressing and releasing operation modes, such as the strength and depth of key pressing operation and the timing of key releasing operation. A case is taken as an example in which although the key is moving in the forward stroke direction, the hammer is moving in the returning direction after making contact with a string or a stopper and being bounced back thereby. In this kind of case, if musical sound is controlled on the basis of only the result of the detection that the hammer has reached a specific position in the forward stroke direction, accurate musical sound control cannot always be carried out in some cases. The player of the musical instrument may feel uncomfortable in some cases, for example, because the timing of key pressing operation does not coincide with the timing of sound generation or the strength of pressing the key does not match the volume of the generated sound.